U.S. patent number 4,283,004 [Application Number 06/066,576] was granted by the patent office on 1981-08-11 for vibration attenuation support assembly for a centrifugal liquid processing apparatus.
This patent grant is currently assigned to Baxter Travenol Laboratories, Inc.. Invention is credited to Rene G. Lamadrid.
United States Patent |
4,283,004 |
Lamadrid |
August 11, 1981 |
Vibration attenuation support assembly for a centrifugal liquid
processing apparatus
Abstract
The vibration attenuation support assembly is utilized in a
centrifugal liquid processing apparatus for supporting a rotor
assembly, a non-rotatable arm fixed to and forming part of the
support assembly and a prime mover and for attenuating vibrations
created by an unbalanced mass in the rotating parts of the
apparatus. The apparatus comprises a cabinet having sidewalls and a
floor and a rotor assembly mounted on the support assembly mounted
on the floor. Tubings are coupled directly between a source of the
liquid outside of the rotor to receptacles within the rotor without
the use of fluid seals and are supported from the stationary arm.
The rotor assembly includes structure for guiding the tubings from
the stationary arm to the rotor and a drive train mechanism and
prime mover for rotating the tubings at a first speed and for
rotating the rotor at a second speed twice the first speed. The
support assembly includes a weldment for supporting the rotor
assembly and prime mover and includes four elastomeric members for
mounting the weldment on the floor. The support assembly has a mass
greater than the unbalanced mass and in one embodiment the support
assembly together with the rotor assembly and prime mover have a
mass of approximately 150 kilograms and the unbalanced mass is 30
grams acting at a radius of 5 inches at a rotation of 1400
revolutions per minute.
Inventors: |
Lamadrid; Rene G. (Bethesda,
MD) |
Assignee: |
Baxter Travenol Laboratories,
Inc. (Deerfield, IL)
|
Family
ID: |
22070385 |
Appl.
No.: |
06/066,576 |
Filed: |
August 15, 1979 |
Current U.S.
Class: |
494/18; 248/615;
494/60; 494/82; 494/84 |
Current CPC
Class: |
B04B
5/0442 (20130101); B01D 21/262 (20130101); B01D
2221/10 (20130101); B01D 2221/08 (20130101) |
Current International
Class: |
B01D
21/26 (20060101); B04B 5/04 (20060101); B04B
5/00 (20060101); B01D 021/26 (); B01D 043/00 () |
Field of
Search: |
;233/1C,1R,23R,23A,24,25,26,27 ;248/615,638 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
695430 |
|
Oct 1964 |
|
CA |
|
809736 |
|
Aug 1951 |
|
DE |
|
313049 |
|
Jul 1930 |
|
GB |
|
Primary Examiner: Gilreath; Stanley N.
Attorney, Agent or Firm: Benziger; Robert A. Vigil; Thomas
R. Flattery; Paul C.
Claims
I claim:
1. In a centrifugal liquid processing apparatus of the type which
is utilized for separating a liquid containing particles, such as
blood, into the components thereof and which includes a cabinet
having sidewalls and a floor, a prime mover within the cabinet, a
rotor assembly which is situated within the cabinet and which
includes a rotor mounting receptacles thereon, tubing coupled
directly between a source of the liquid outside the rotor to the
receptacles within the rotor without the use of fluid seals, a
non-rotatable arm within the cabinet for holding the tubings and
for directing the tubings toward the rotor assembly and rotatable
tubing guide means for guiding the tubings from the holder to the
rotor, the tubing guide means being mounted for coaxial rotation
with the rotor, and the rotor assembly including drive train means
for coupling the prime mover to the rotor and to the tubing guide
means for rotating the tubing guide means at a first speed and for
rotating the rotor at a second speed twice the first speed to
prevent the tubings from becoming entangled, the improvement
comprising a vibration attenuation support means for supporting the
rotor assembly, the non-rotatable arm which is fixed to and forms
part of said support means, and the prime mover on the floor of the
cabinet and for attenuating the vibrations produced as a result of
an unbalanced mass in the rotating parts of the apparatus thereby
reducing the transmission of such vibrations to the cabinet, said
vibration attenuation support means comprising an attenuation and
support assembly including a weldment on which the rotor assembly,
the prime mover, and said non-rotatable arm are mounted, and
elastomeric means for supporting said weldment on the floor of the
cabinet and the ratio of the unbalanced mass to the mass of said
weldment, said arm, the rotor assembly and the prime mover being
between 1:1000 and 1:10,000.
2. The apparatus according to claim 1 wherein said elastomeric
means comprise a plurality of frusto-conical elastomeric
members.
3. The apparatus according to claim 2 wherein said elastomeric
means comprise four of said elastomeric members.
4. The apparatus according to claim 1 wherein said weldment
comprises a generally rectangular framework and a generally
horizontally extending first plate which is secured to said
framework and which has an opening therethrough, the rotor assembly
being secured to said first plate with a portion of the drive train
means extending through said opening.
5. The apparatus according to claim 4 wherein said framework
comprises two long frame members, wherein the long dimension of
said rectangular framework is longer than the corresponding
dimension of said first plate to provide a space in said weldment
adjacent one end edge of said first plate and between said two long
frame members, the portions of said long frame members extending
beyond said first plate forming support arms and wherein said
weldment includes a second generally horizontally extending plate
which is fixed in said space and which has an opening therethrough,
the prime mover being mounted on said second plate with a drive
shaft thereof extending through said openings.
6. The apparatus according to claim 4 wherein said weldment
includes a plurality of mounting brackets attached to the sides of
said rectangular framework for mounting said elastomeric supports,
said elastomeric supports being attached between said mounting
brackets and the floor of the cabinet.
7. The apparatus according to claim 5 wherein said rotor assembly
includes a bearing mounted on said first plate coaxial with said
opening therethrough, the drive train means including a shaft
rotatably supported by the bearing and extending beneath said first
plate and wherein the drive train means includes a pulley on the
end of the shaft beneath the first plate, a pulley on the shaft of
the prime mover beneath the second plate and a belt drivingly
coupling the pulleys beneath said first and second plates and
within said framework.
8. The apparatus according to claim 7 wherein said weldment
includes two upright members each fixed to a corner of said plate
adjacent said space and a cross member fixed to and between said
upright members, said non-rotatable arm being fixed to and
extending outwardly from said cross member, with said arm
intersecting the rotational axis of the rotor.
9. The apparatus according to claim 5 wherein said rectangular
framework further comprises first and second short end members,
said short end members each being attached generally perpendicular
to and between said long members at one end of said framework, said
first plate resting on and being secured to said first short member
and a portion of said two long members, a first cross member fixed
between said long members, generally parallel to and spaced
inwardly from a second end member and beneath said one end edge of
said first plate, a second cross member fixed to and between said
second end member and said first cross member and generally
parallel to said first and second long members, said second plate
resing on and being secured to one of said arm portions and said
second cross member.
10. The apparatus according to claim 9 wherein said weldment
includes two upright members each fixed to a corner of said plate
adjacent said space and a third cross member fixed to and between
said upright members, said non-rotatable arm being fixed to and
extending outwardly from said cross member, with the arm
intersecting the rotational axis of the rotor.
11. The apparatus according to claim 1 wherein the rotor is driven
at a rotational speed between 1000 and 2000 revolutions per
minute.
12. The apparatus according to claim 11 wherein said rotor is
driven at approximately 1400 revolutions per minute.
13. The apparatus according to claim 1 wherein the unbalanced mass
acts at a radius between 1 inch and 8 inches from the axis of
rotation of the rotor.
14. The apparatus according to claim 13 wherein the unbalanced mass
acts at a radius of approximately 5 inches from the axis of
rotation of the rotor.
15. The apparatus according to claim 1 wherein the ratio of the
unbalanced mass to the total mass of said weldment, the rotor
assembly, said arm and the prime mover is approximately 1 to
5000.
16. The apparatus according to claim 1 wherein the unbalanced mass
is not greater than 45 grams and the total mass of said weldment,
the rotor assembly, said arm and the prime mover is between 45
kilograms and 450 kilograms.
17. The apparatus according to claim 16 wherein the unbalanced mass
is approximately 30 grams and the total mass of said weldment, the
rotor assembly, said arm and the prime mover is approximately 150
kilograms.
18. The apparatus according to claim 1 wherein the rotor is driven
at a rotational speed between 1000 and 2000 revolutions per minute,
said unbalanced mass acts at a radius between 1 and 8 inches from
the axis of rotation of the rotor and is not greater than 45 grams,
and the mass of said weldment, the rotor assembly, said arm and the
prime mover is between 45 kilograms and 450 kilograms.
19. The apparatus according to claim 1 wherein the rotor is driven
at a speed of approximately 1400 revolutions per minute, the
unbalanced mass acts at a radius of approximately 5 inches from the
axis of rotation of the rotor and is approximately 30 grams and the
mass of said weldment, the rotor assembly, said arm and the prime
mover is approximately 150 kilograms.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vibration attenuation support
assembly for supporting a rotor assembly and a prime mover therefor
in a centrifugal liquid processing apparatus for separating whole
blood into the components thereof.
2. Description of the Prior Art
Heretofore various apparatus have been proposed for the separation
of whole blood into its component parts. In one such apparatus a
continuous tubing is coupled from a source of blood situated
outside of the apparatus to a receptacle on a rotor inside the
apparatus. A return tubing is coupled from the rotor receptacle to
a stationary receptacle situated outside of the rotor. Apparatus of
this type are disclosed in U.S. Pat. No. 3,986,442 entitled: DRIVE
SYSTEM FOR A CENTRIFUGAL LIQUID PROCESSING SYSTEM, U.S. Pat. No.
4,127,231 entitled: SUPPORT ARM FOR CENTRIFUGAL LIQUID PROCESSING
APPARATUS, U.S. Pat. No. 4,132,349 entitled: ROTOR DRIVE ASSEMBLY
FOR A CENTRIFUGAL LIQUID PROCESSING APPARATUS, and U.S. Pat. No.
4,146,172 entitled: CENTRIFUGAL LIQUID PROCESSING SYSTEM, the
disclosures of which are incorporated herein by reference.
Also, the technique for coupling lines such as tubing or wires
directly to a rotor and for preventing the lines from becoming
entangled during rotation of the rotor is disclosed in U.S. Pat.
No. 3,586,413 entitled: APPARATUS FOR PROVIDING ENERGY
COMMUNICATION BETWEEN A MOVING AND A STATIONARY TERMINAL, the
disclosure of which is incorporated herein by reference.
Heretofore the rotor assembly and prime mover of the centrifugal
liquid processing apparatus have been supported on the floor of the
cabinet. When an unbalanced rotating mass is incurred, significant
vibrations are developed in the rotation of the rotor which are
transmitted to the cabinet and are very irritating to an operator
in addition to causing wear of the parts of the apparatus. The
unbalanced mass is caused by several factors, including density
variations in the liquid contained within the rotor of the
apparatus, the unsymmetrical location of receptacles mounted in the
rotor, rotating of the tubings about the rotor and the flexing of
the tubing as it continuously twists and untwists.
Vibrations produced by an unbalanced rotating mass have long been a
problem in the utilization of rotating machinery and various
structures have been disclosed for isolating and attenuating
vibrations produced in rotating machinery.
Examples of centrifugal liquid processing apparatus and vibration
isolation structures for attenuating vibrations produced by an
unbalanced rotating mass can be found in the following U.S.
Patents.
______________________________________ U.S. PAT. NO. PATENTEE
______________________________________ 1,723,940 Krantz 2,521,054
Ellis 2,637,514 O'Connor 2,987,189 Evjen 3,249,215 Kelly 3,363,772
Jarvis 3,452,924 Schultz 3,509,742 Bauer 3,580,014 Mazza 3,774,710
McCartney 3,824,701 Norquist 3,945,226 de Hedouville 3,986,442
Khoja et al. 4,113,173 Lolachi
______________________________________
In U.S. Pat. No. 2,637,514 there is disclosed a garment treating
machine such as a clothes washer or dryer which has a drum mounted
for rotation about a horizontal axis. A cabinet of the machine is
mounted on springs and fixed at its center by a pivotal mounting.
This mounting arrangement allows the apparatus to pitch forward and
backward, left and right, and up and down, such movement being
restrained by the pivotal central mounting.
In U.S. Pat. No. 3,824,701 there is disclosed a portable
centrifugal drier for small articles, having a motor and a
frustoconical housing mounted for rotation about a vertical axis on
a stabilizing weight disk which is supported on a flat surface by
nonskid, resilient, shock absorbing elastomeric feet.
In U.S. Pat. No. 3,580,014 there is disclosed a washing machine
furnished with ballast. According to the teachings of this patent,
the ballast comprises two containers which can be charged with
water to suppress the vibrational motion developed in the washing
machine by either a reciprocating motion or a rotary motion. The
containers are deformable and can be inflated with air.
As will be described in greater detail hereinafter, the vibration
attenuation support assembly of the present invention differs from
the previously proposed vibration suppression structures by
providing a support assembly for use in a centrifugal liquid
processing apparatus where tubings are directly coupled between
receptacles inside of and outside of a rotating rotor assembly and
where a tubing guide which is part of the rotor assembly and which
is coaxial with the rotor is rotated at a first speed and the rotor
is rotated at a second speed twice the first speed to prevent the
tubing from becoming entangled. The support assembly supports (a)
the rotor assembly, (b) a prime mover therefor, and (c) a
non-rotatable arm fixed to and forming part of the support assembly
for directing the tubing toward the rotor assembly along the axis
of rotation of the rotor assembly and attenuates vibration produced
as a result of an unbalanced mass in the rotating parts of the
apparatus.
SUMMARY OF THE INVENTION
According to the present invention there is provided in a
centrifugal liquid processing apparatus of the type which is
utilized for separating a liquid containing particles, such as
blood, into the components thereof and which includes a cabinet
having sidewalls and a floor, a prime mover within the cabinet, a
rotor assembly which is situated within the cabinet and which
includes a rotor mounting receptacles thereon, tubing coupled
directly between a source of the liquid outside the rotor to the
receptacles within the rotor without the use of fluid seals, a
non-rotatable arm within the cabinet for holding the tubings and
for directing the tubings toward the rotor assembly and rotatable
tubing guide means for guiding the tubings from the holder to the
rotor, the tubing guide means being mounted for coaxial rotation
with the rotor, and the rotor assembly including drive train means
for coupling the prime mover to the rotor and to the tubing guide
means for rotating the tubing guide means at a first speed and for
rotating the rotor at a second speed twice the first speed to
prevent the tubings from becoming entangled, the improvement
comprising a vibration attenuation support means for supporting the
rotor assembly, the non-rotatable arm which is fixed to and forms
part of said support means, and the prime mover on the floor of the
cabinet and for attenuating the vibrations produced as a result of
an unbalanced mass in the rotating parts of the apparatus thereby
reducing the transmission of such vibrations to the cabinet, said
vibration attenuation support means comprising an attenuation and
support assembly including a weldment on which the rotor assembly,
the prime mover, and said non-rotatable arm are mounted, and
elastomeric means for supporting said weldment on the floor of the
cabinet and the ratio of the unbalanced mass to the mass of said
weldment, said arm, the rotor assembly and the prime mover being
between 1:1000 and 1:10,000.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a centrifugal liquid processing
apparatus and shows in phantom lines the location of a prime mover
and rotor assembly of the apparatus.
FIG. 2 is a vertical fragmentary sectional view of a lower corner
of the apparatus and shows an elastomeric member at a corner of a
weldment of the vibration attenuation support assembly of the
present invention which is utilized in the apparatus shown in FIG.
1.
FIG. 3 is a perspective view of the apparatus shown in FIG. 1 with
a top cabinet thereof removed to show the rotor assembly, the prime
mover and a non-rotatable support arm for tubings utilized in the
apparatus all supported on the vibration attenuation support
assembly of the present invention.
FIG. 4 is a perspective view of the vibration attenuation support
assembly viewing the same from one corner thereof with the rotor
assembly removed.
FIG. 5 is a perspective view of the vibration attenuation support
assembly viewing the same from another corner thereof with the
rotor assembly removed.
FIG. 6 is a perspective bottom view of the vibration attenuation
support assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in greater detail there is
illustrated in FIG. 1 a centrifugal liquid processing apparatus 10
particularly adapted for separating whole blood into the components
thereof. The apparatus 10 is of the type known as the CELL
SEPARATOR sold by the Instrument Division of Travenol Laboratories,
Inc. of Deerfield, Ill. The apparatus 10 comprises a rotor assembly
12 including a rotor 14 (FIG. 3) and two pairs of platens 16 and 18
mounted on the rotor 14 and having liquid receiving receptacles
clamped therein.
As will be explained in greater detail hereinafter, the rotor
assembly 12 is mounted on a vibration attenuation support assembly
20 which is constructed according to the teachings of the present
invention. The support assembly 20 in turn is mounted on a floor 22
of a base 24 on which is mounted a cabinet 26 enclosing the
assemblies 12 and 20.
A prime mover 28 is mounted on the support assembly 20 and is
drivingly coupled to a rotor drive 30 situated beneath and
supporting the rotor 14 and forming part of the rotor assembly 12.
The rotor assembly 12 further includes a tubing guide structure 32
comprising a drum 34 which is mounted coaxially with the rotor 14
and a pin 36 which extends from the drum 34 and which is adapted to
engage an umbilical tubing 37 having several smaller diameter
tubings therein.
A non-rotatable arm 38 is supported on the support assembly 20 with
its outer end 40 located on the axis of rotation of the rotor 14.
The non-rotatable arm 38 is adapted to guide the umbilical tubing
37 having several smaller diameter tubings therein from a source of
liquid (not shown) such as a blood bag, a donor or a patient
situated external to the rotor assembly 12 to the receptacles
mounted between the platens 16 and 18 on the rotor 14.
The rotor drive 30 is of known type and is constructed and arranged
to rotate the tubing guide structure 32 at a first speed and the
rotor 14 at a second speed which is twice the first speed.
As disclosed in U.S. Pat. No. 3,586,413 referred to above, by
rotating the tubing guide structure 32 so that the pin 26 engages
the umbilical tubing 37 and rotates the same at a speed which is
one half the speed of rotation of the rotor 14, the umbilical
tubing 37 is caused to twist and untwist upon each rotation of the
tubing guide structure 32.
In the operation of the apparatus 10, liquid such as whole blood is
supplied to one of the receptacles and centrifuged to cause
separation of the whole blood into its components, namely red blood
cells, white blood cells, platelets and plasma. Then, certain of
the components are withdrawn from certain points in the separation
receptacle and collected in the receptacle within the rotor
assembly 12 and a receptacle outside of the rotor assembly 12.
Since the weight and positioning of the two pairs of platens 16 and
18 is not uniform, since the mass of the tubings and liquids
therein is usually unbalanced, and since there are different masses
of liquid in the receptacles positioned between each pair of
platens 16 and 18, an unbalanced rotating mass is developed as the
liquid is being processed during rotation of the rotor assembly 12.
At speeds of rotation from 1000 to 2000 rpm, this results in
vibrations being created during rotation of the rotor assembly 12,
which vibrations are not only annoying by causing the cabinet 26 to
vibrate, but also wearing on components of the apparatus 10. The
twisting and untwisting of the umbilical tubing 37 in an orbital
path about the rotor axis causes the umbilical tubing 37 to exert
forces on the non-rotatable arm 38 that also contribute to the
vibrations.
According to the teachings of the present invention, this annoying
vibration developed as a result of an unbalanced rotating mass is
minimized by the vibration attenuation support assembly 20 of the
present invention.
The vibration attenuation support assembly 20 comprises a metal
(e.g., steel) weldment 50 including a horizontal framework 52 on
which is welded a first plate 54, an upright framework 56 welded to
the first plate 54 and positioned to support the arm 38 over the
rotor assembly 12 and, at least four frusto-conical elastomeric
support members 58 of known type fixed to the framework 52 for
supporting the weldment 50 on the floor 22 of the base 24 of the
cabinet 26 as best shown in FIGS. 4 and 5. Forces on the arm 38 are
transmitted by the upright framework 56 to the weldment 50 and
attenuated thereby without being transmitted to the cabinet 26.
As shown in FIGS. 4, 5 and 6, the horizontal framework 52 is
generally rectangular and includes first and second long frame
members 62 and 64 interconnected by first and second short end
members 66 and 68, all or which have L or channel cross sections.
Fixed to and above the first and second long frame members 62 and
64 and the first short end member 66 is the first plate 54 which
has a central circular opening 70 therein for receiving and
mounting the rotor assembly 12. More specifically, a shaft 72 (FIG.
3) of the rotor 14 is supported by a bearing 74 on a base plate 76
which is secured to and on the first plate 54 such that the lower
end of the shaft 72 with a pulley (not shown) thereon, is
positioned beneath the first plate 54 within the framework 52.
As shown, the four frusto-conical elastomeric support members 58
are each secured by means of an L shaped mounting bracket 80 to the
side of one of the long frame members 62 or 64. At the bottom of
each of the elastomeric members 58 is a mounting flange 81 for
securing each elastomeric member 58 to the floor 22 of the base 24
of the cabinet 26.
As best shown in FIG. 5, the two long frame members 62 and 64 have
a portion cut away at one end thereof to provide reduced width arm
portions 82 and 84. Also it will be noted that the first plate 54
is shorter than the long frame members 62 and 64 so that it only
extends to shoulders 86,88 (FIG. 5) at the cut away portion of each
long frame member 62,64.
As shown in FIG. 5, the second short end member 68 is a piece of
angle iron which as an L shaped cross section and which extends
between and is secured to the reduced width arm portions 82,84 of
the long frame members 62,64. Another short frame member 90 extends
between the long frame members 62,64 at a point beneath one edge 93
of the first plate 54 generally parallel to the second short end
member 68. A cross member 96 is fixed to and between the second
short end member 68 and the short frame member 90. A second smaller
plate 98 is secured on and between the first arm portion 82 and the
cross member 96 and has mounted thereon the prime mover 28 which is
typically an electric motor. The shaft of the electric motor 28
extends below the second plate 98 and has a pulley 100 (FIG. 6)
mounted thereon and a belt 101 (FIG. 1) coupling pulley 100 to the
pulley on shaft 72 within the framework 52.
The upright framework 56 includes a horizontally extending L cross
section frame member 102 and first and second upright L cross
section frame members 104 and 106. Also the upright framework 56
includes first and second support plates 108 and 110 at the lower
corners of the upright framework 56 and first and second pairs 112,
114 of trianbular braces which are fixed to and between the upright
frame members and the support plates 108, 110 which are welded to
the first plate 54.
Mounted to and extending between the upper ends of the upright
frame members 104 and 106 is a cross arm 120 (FIG. 4) having each
end thereof fixed to the upper end of one of the frame members 104
and 106. The non-rotatable arm 38 is integral with, extends from
and forms a T with the cross arm 120 as shown in FIG. 4. The
stationary arm 38 has an aperture 123 therein through which the
umbilical tubing 37 is received.
In the use of the apparatus 10, studies and tests were made with an
unbalanced rotating mass in the rotating parts of the rotor
assembly 12 such as an unbalanced mass of from 1 to 45 grams acting
at a radius of from 1 to 8 inches with the rotor 14 rotating at a
speed from 1000 rpm to 2000 rmp and it was found that satisfactory
attenuation of vibrations developed by the unbalanced mass was
obtained with the weldment and arm 38, rotor assembly 12 and prime
mover 28 mounted thereon having a mass of between 45 kilograms and
450 kilograms.
More specifically, in a preferred embodiment of the apparatus 10,
satisfactory attenuation of vibrations developed by an unbalanced
rotating mass of approximately 30 grams acting at a radius of 5
inches from the axis of rotation of the rotor 14 rotating at a
rotational speed of approximately 1400 rpm, was obtained by
providing a weldment 50 and arm 38, rotor assembly 12 and prime
mover 28 mounted thereon in the assembly 20 having a mass of 150
kilograms.
From the parameters of one preferred embodiment and from the
empirical studies and tests conducted, it appears that a ratio of
the unbalanced mass to the mass of the weldment 50 and arm 38,
rotor assembly 12 and the prime mover 28 mounted thereon of between
1 to 1000 and 1 to 10,000 provides satisfactory attenuation of
vibrations. A preferred ratio of the unbalanced mass to the mass of
the weldment 50 and arm 38, rotor assembly 12 and prime mover 28
mounted thereon is 1 to 5000.
Also, of course, the height of the unbalanced mass within the
rotating parts of the rotor assembly above the first plate 54
should be kept as low as possible.
From the foregoing description it will be apparent that the
vibration attenuating support assembly 20 in the apparatus 10 of
the present invention provides for satisfactory attenuation of the
vibrations developed by an unbalanced rotating mass in the rotating
parts of the apparatus 10. Also it will be apparent that obvious
modifications can be made to the assembly 20 without departing from
the teachings of the invention. Accordingly, the scope of the
invention is only to be limited as necessitated by the accompanying
claims.
* * * * *